Neuropediatrics 2006; 37 - MP64
DOI: 10.1055/s-2006-943661

CLINICAL MANIFESTATIONS OF MITOCHONDRIAL DISEASES IN INFANTS AND CHILDREN

HF Lee 1, CS Chi 1, CR Tsai 1, CH Chen 1, LH Chen 1
  • 1Department of Pediatrics, Taichung Veterans General Hospital, Taichung-Kang Road, Taichung, Taiwan

Mitochondrial diseases represent one of the most exciting of chapters of modern medicine. It has been noticed in infants and children over the last decades. However, early detection of a case with mitochondrial dysfunction by clinical features still challenge to pediatric neurologists.

From 1983 to December 2005, we collected 50 cases, 29 male and 21 female, aged from 3 months to 14 years. The diagnosis of mitochondrial diseases was made by clinical manifestations together with abnormal muscle mitochondrial morphologies±mitochondrial gene determination and oral glucose lactate stimulation test. Those patients included 14 Leigh syndrome, 2 Kearns-Sayre syndrome, 3 mitochondrial encephalopathy lactic acidosis stroke-like episode, 1 myoclonic epilepsy with ragged red fibers, 1 fatal infantile mitochondrial myopathy, 3 fatty acid oxidation defects, 4 mitochondrial cardiomyopathy±myopathy, 1 Leber hereditary optic neuropathy, 1 mitochondrial neuropathy gastrointestinal encephalopathy, 1 dystonia deafness syndrome, 1 chronic progressive external ophthalmoplegia, 1 Pearson syndrome, 17 unclassified mitochondrial syndromes.

The clinical manifestations of pediatric mitochondrial diseases varied. Grossly, we divided into two parts in terms of neuromuscular system and non-neuromuscular system. In neuromuscular system, 44 out of 50 cases (88.0%) presented clinical manifestations of central nervous syndrome, including altered level of consciousness, headache, seizures, mental retardation, developmental delay, floppiness, sucking/swallowing difficulty, apnea, apneustic respiration, ophthalmoplegia, spasticity, dystonia, tremor, and ataxia; 2 out of 50 cases (4.0%) had peripheral neuropathy; 7 out of 50 cases (14.0%) had muscular symptoms in terms of muscle wasting, exercise intolerance, muscle weakness. In non-neuromuscular system, mitochondrial diseases could involve multiple organs, including ophthalmic system (34.0%), auditory system (10.0%), cardiovascular system (24.0%), gastrointestinal system (18.0%), hepatic system (14.0%), pancreatic system (2.0%), urologic system (10.0%), endocrinologic system (4.0%), hematologic system (2.0%), short statute (20.0%) and failure to thrive (34.0%).

In conclusion, mitochondrial diseases in infants and children have diverse clinical presentations and it should be included as the differential diagnosis in cases of multiorgan involvement, especially symptoms of non-neuromuscular systems.